The requirements for determining the location, orientation and surface curvature of an object are particularly evident in manufacturing and production operations wherein a workpiece or product undergoes a series of handling or processing steps. These requirements are especially critical when the various handling and process steps are the responsibility of machine tools, mechanical manipulators or robots. Typically, proximity sensing devices for monitoring a workpiece operate in either an on-off or continuous mode and can be classified as visual or non-visual, contact or non-contact, and long range or short range.